Scaling of the temperature-dependent resistivity in 122 iron-pnictide superconductors

Abstract

In various electron-doped Ba(Fe1 − xCox)2As2 (x = 0–0.3) andhole-doped Ba1 − xKxFe2As2 (x = 0–1) members of the 122-iron-pnictide superconductor family, the temperature-dependent resistivityρ can be scaled into a universal curve. It is found that theρ(T) dependences can be reproduced by the formulae and in the case of electron and hole doping, respectively. The scaling was performed using the energy scale2Δ,c and the residualresistivity ρ0 as scaling parameters. The scaling parameters have been calculated and the compositional variation of2Δ andρ0 has been determined. The existence of universal metallicρ(T) curvesin Ba(Fe1 − xCox)2As2 (x = 0–0.3)and Ba1 − xKxFe2As2 (x = 0–1) is interpreted as an indication of a single mechanism in each compound whichdominates the different scattering of the charge carriers in both compounds. Thus, thescaling of the normal state properties seems to be a general feature not only for high-Tc cuprates but also for the iron-pnictides superconductor family in both under- and overdopedregimes.